Thyroid Cancer Screening and Diagnosis

Thyroid Cancer Screening

• Screening is crucial in thyroid cancer diagnosis
• More than 50% of the population over 40 years old have thyroid nodules, but only 5-10% are palpable
• 95% of thyroid nodules are benign
• Thyroid cancer is more common in women than men, at a ratio of 4:1

Thyroid Nodule Diagnosis

• Thyroid nodules can be incidental findings on imaging studies
• A thyroid nodule can be solid, semi-solid, or liquid
• If a nodule is solid or semi-solid, it requires further study
• TSH (thyroid-stimulating hormone) and ultrasound are used to evaluate thyroid nodules

TSH Interpretation

• Low TSH (<0.5) suggests a high probability of thyroid cancer
• Normal TSH (0.5-5) indicates a lower probability of thyroid cancer
• High TSH (>5) may indicate hypothyroidism

Ultrasound Features

• Marginal irregularities, microcalcifications, and extrathyroidal extension are characteristics of high-risk thyroid nodules
• These features increase the likelihood of thyroid cancer

Biopsy and Cytology

• Biopsy is necessary for thyroid nodules with high-risk ultrasound features
• Cytology categorizes thyroid nodules into six categories:
  • Insufficient (1)
  • Benign (2)
  • Indeterminate (3)
  • Follicular neoplasm (4)
  • Suspicious for malignancy (5)
  • Malignant (6)

Thyroid Cancer Classification

• Thyroid cancer can be classified into four main types:
  • Papillary carcinoma (85% of all thyroid cancers)
  • Follicular carcinoma (12% of all thyroid cancers)
  • Anaplastic carcinoma (3% of all thyroid cancers)
  • Medullary carcinoma (rare, associated with multiple endocrine neoplasia)

Treatment

• Well-differentiated thyroid cancers (papillary and follicular) are typically treated with surgery and radioactive iodine ablation
• Poorly differentiated thyroid cancers (anaplastic and medullary) are treated with surgery, radiation therapy, and chemotherapy
• Suppressive thyroid hormone treatment is also used in some cases

Thyroid Cancer Screening

• More than 50% of the population over 40 years old have thyroid nodules, but only 5-10% are palpable
• 95% of thyroid nodules are benign
• Thyroid cancer is more common in women than men, at a ratio of 4:1

Thyroid Nodule Diagnosis

• Thyroid nodules can be incidental findings on imaging studies
• A thyroid nodule can be solid, semi-solid, or liquid
• Solid or semi-solid nodules require further study
• TSH and ultrasound are used to evaluate thyroid nodules

TSH Interpretation

• Low TSH may indicate hypothyroidism

Ultrasound Features

• Marginal irregularities, microcalcifications, and extrathyroidal extension are characteristics of high-risk thyroid nodules
• These features increase the likelihood of thyroid cancer

Biopsy and Cytology

• Biopsy is necessary for thyroid nodules with high-risk ultrasound features
• Cytology categorizes thyroid nodules into six categories:
  • Insufficient
  • Benign
  • Indeterminate
  • Follicular neoplasm
  • Suspicious for malignancy
  • Malignant

Thyroid Cancer Classification

• Thyroid cancer can be classified into four main types:
  • Papillary carcinoma (85% of all thyroid cancers)
  • Follicular carcinoma (12% of all thyroid cancers)
  • Anaplastic carcinoma (3% of all thyroid cancers)
  • Medullary carcinoma (rare, associated with multiple endocrine neoplasia)

Treatment

• Well-differentiated thyroid cancers (papillary and follicular) are typically treated with surgery and radioactive iodine ablation
• Poorly differentiated thyroid cancers (anaplastic and medullary) are treated with surgery, radiation therapy, and chemotherapy
• Suppressive thyroid hormone treatment is also used in some cases